Examinando por Autor "Simirgiotis, Mario J."
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Ítem A new mulinane diterpenoid from the cushion shrub Azorella compacta growing in Perú(Medknow Publications, 2014-07) Salgado, Francisco; Areche, Carlos; Sepúlveda, Beatriz; Simirgiotis, Mario J.; Cáceres, Fátima; Quispe, Cristina; Quispe, Lina; Cano, TeresaBackground: Azorella compacta is a rare yellow‑green compact resinous cushion shrub growing from the high Andes of southern Perú to northwestern Argentina, and which is a producer of biologically active and unique diterpenoids. Objective: This study investigated the secondary metabolites present in a Peruvian sample of Azorella compacta and the evaluation of gastroprotective activity of the isolated compounds in a gastric‑ induced ulcer model in mice. Material and Methods: Six secondary metabolites (diterpenoids 1‑6) present in the dichloromethane (DCM) extract of A. compacta growing in Perú were isolated by a combination of Sephadex LH‑20 permeation and silica gel chromatography and their chemical structures were elucidated by spectroscopic methods (NMR) and molecular modeling. The gastroprotective activity of the new compound 1 was evaluated on the HCl/EtOH‑induced gastric lesion model in mice and compared to the activity showed by the known compounds. Results: A new mulinane diterpene along with five known diterpenoids have been isolated from a Peruvian sample of A. compacta and the gastroprotective results show that compound 1 is less active than the other known mulinane diterpenoids isolated. Conclusions: A. compacta growing in Perú showed the presence of the new mulinane 1, which was poorly active in the HCl/EtOH‑induced gastric lesion model in mice. Indeed, the activity was lower than other diterpenoids (2‑6) showing an oxygenated function at C‑16 or/and C‑20, which confirm the role of an oxygenated group (OH or carboxylic acid) for the gastroprotective activity of mulinane compounds.Ítem Anthocyanin characterization, total phenolic quantification and antioxidant features of some chilean edible berry extracts(MDPI, 2014-07) Brito, Anghel; Areche, Carlos; Sepúlveda, Beatriz; Kennelly, Edward J.; Simirgiotis, Mario J.The anthocyanin composition and HPLC fingerprints of six small berries endemic of the VIII region of Chile were investigated using high resolution mass analysis for the first time (HR-ToF-ESI-MS). The antioxidant features of the six endemic species were compared, including a variety of blueberries which is one of the most commercially significant berry crops in Chile. The anthocyanin fingerprints obtained for the fruits were compared and correlated with the antioxidant features measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP), the superoxide anion scavenging activity assay (SA), and total content of phenolics, flavonoids and anthocyanins measured by spectroscopic methods. Thirty one anthocyanins were identified, and the major ones were quantified by HPLC-DAD, mostly branched 3-O-glycosides of delphinidin, cyanidin, petunidin, peonidin and malvidin. Three phenolic acids (feruloylquinic acid, chlorogenic acid, and neochlorogenic acid) and five flavonols (hyperoside, isoquercitrin, quercetin, rutin, myricetin and isorhamnetin) were also identified. Calafate fruits showed the highest antioxidant activity (2.33 ± 0.21 μg/mL in the DPPH assay), followed by blueberry (3.32 ± 0.18 μg/mL), and arrayán (5.88 ± 0.21), respectively. © 2014 by the authors.Ítem Antioxidant capacities and analysis of phenolic compounds in three endemic nolana species by HPLC-PDA-ESI-MS(MDPI AG, 2015-06) Simirgiotis, Mario J.; Benites, Julio; Areche, Carlos; Sepu, BeatrizThe antioxidant features, polyphenolic composition and chromatographic fingerprints of the aerial parts from three Chilean endemic plants from the Paposo Valley located on the cost of the Atacama Desert were investigated for the first time using high pressure liquid chromatography coupled with photodiode array detector and electrospray ionization mass analysis (HPLC-PDA-ESI-MS) and spectroscopic methods. The phenolic fingerprints obtained for the plants were compared and correlated with the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP) and quantification of the total content of phenolics and flavonoids measured by spectroscopic methods. Thirty phenolics were identified for the first time for these species, mostly phenolic acids, flavanones, flavonols and some of their glycoside derivatives, together with three saturated fatty acids (stearic, palmitic and arachidic acids). Nolana ramosissima showed the highest antioxidant activity (26.35 ± 1.02 μg/mL, 116.07 ± 3.42 μM Trolox equivalents/g dry weight and 81.23% ± 3.77% of inhibition in the DPPH, FRAP and scavenging activity (SA) assays, respectively), followed by N. aplocaryoides (85.19 ± 1.64 μg/mL, 65.87 ± 2.33 μM TE/g DW and 53.27% ± 3.07%) and N. leptophylla (124.71 ± 3.01, 44.23 ± 5.18 μM TE/g DW and 38.63% ± 1.85%). © 2015 by the authors.Ítem Antioxidant properties and hyphenated HPLC-PDA-MS profiling of chilean pica mango fruits (Mangifera indica L. Cv. piqueño)(MDPI, 2013-12) Ramirez, Javier E.; Zambrano, Ricardo; Sepúlveda, Beatriz; Simirgiotis, Mario J.Antioxidant capacities and polyphenolic contents of two mango cultivars from northern Chile, one of them endemic of an oasis in the Atacama Desert, were compared for the first time. Twenty one phenolic compounds were detected in peel and pulp of mango fruits varieties Pica and Tommy Atkins by HPLC-PDA-MS and tentatively characterized. Eighteen compounds were present in Pica pulp (ppu), 13 in Pica peel (ppe) 11 in Tommy Atkins pulp (tpu) and 12 in Tommy Atkins peel (tpe). Three procyanidin dimers (peaks 6, 9 and 10), seven acid derivatives (peaks 1-4, 11, 20 and 21) and four xanthones were identified, mainly mangiferin (peak 12) and mangiferin gallate, (peak 7), which were present in both peel and pulp of the two studied species from northern Chile. Homomangiferin (peak 13) was also present in both fruit pulps and dimethylmangiferin (peak 14) was present only in Tommy pulp. Pica fruits showed better antioxidant capacities and higher polyphenolic content (73.76/32.23 μg/mL in the DPPH assay and 32.49/72.01 mg GAE/100 g fresh material in the TPC assay, for edible pulp and peel, respectively) than Tommy Atkins fruits (127.22/46.39 μg/mL in the DPPH assay and 25.03/72.01 mg GAE/100 g fresh material in the TPC assay for pulp and peel, respectively). The peel of Pica mangoes showed also the highest content of phenolics (66.02 mg/100 g FW) measured by HPLC-PDA. The HPLC generated fingerprint can be used to authenticate Pica mango fruits and Pica mango food products.© 2014 by the authors licensee MDPI Basel Switzerland.Ítem Concise and straightforward asymmetric synthesis of a cyclic natural hydroxy-amino acid(MDPI AG, 2014) Simirgiotis, Mario J.; Vallejos, Javier; Areche, Carlos; Sepúlveda, BeatrizAn enantioselective total synthesis of the natural amino acid (2S,4R,5R)-4,5-dihydroxy-pipecolic acid starting from D-glucoheptono-1, 4-lactone is presented. The best sequence employed as a key step the intramolecular nucleophilic displacement by an amino function of a 6-O-p-toluene-sulphonyl derivative of a methyl D-arabino-hexonate and involved only 12 steps with an overall yield of 19%. The structures of the compounds synthesized were elucidated on the basis of comprehensive spectroscopic (NMR and MS) and computational analysis. © 2014 by the authors; licensee MDPI, Basel, Switzerland.Ítem Fast detection of phenolic compounds in extracts of easter pears (pyrus communis) from the atacama desert by ultrahigh-performance liquid chromatography and mass spectrometry (UHPLC-Q/Orbitrap/MS/MS)(MDPI AG, 2016-01) Simirgiotis, Mario J.; Quispe, Cristina; Bórquez, Jorge; Areche, Carlos; Sepúlveda, BeatrizA small Chilean variety of pears growing in the town of Toconao, an oasis located at the northeastern edge of the Salar de Atacama, northern Chile, was studied by means of modern PDA and high resolution mass spectral data (UHPLC-PDA-HESI-orbitrap-MS/MS). In addition, the antioxidant features of the fruits were compared with the varieties Packhman’s Triumph and Abate Fetel and correlated with the presence of phenolic compounds. The non-pigmented phenolics were fingerprinted and related to the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP), the superoxide anion scavenging activity assay (SA), and total content of phenolics and flavonoids measured by spectroscopic methods. The machine allowed a fast separation of 15 min employing a flow rate of 1 mL per minute and could accurately identify 25 compounds, including several isorhamnetin derivatives and phenolic acids, present in the peel and pulps of this Chilean variety for the first time. The compounds were monitored using a wavelength range of 210–800 nm. The native small Chilean pear showed the highest antioxidant activity measured as the bleaching of the DPPH radical, the ferric reducing antioxidant power and superoxide anion scavenging activity (8.61 ˘ 0.65 µg/mL, 712.63 ˘ 12.12 micromols trolox equivalents (µmol/TE)/100 g FW, and 82.89% ˘ 2.52% at 100 µg/mL, respectively).Ítem HPLC-UV-MS profiles of phenolic compounds and antioxidant activity of fruits from three citrus species consumed in Northern Chile(MDPI AG, 2014) Brito, Anghel; Ramirez, Javier E.; Areche, Carlos; Sepúlveda, Beatriz; Simirgiotis, Mario J.Peels and edible pulp from three species of citrus including Citrus aurantifolia (varieties pica and sutil) and Citrus x lemon var. Genova widely cultivated and consumed in Northern Chile (I and II region) were analyzed for phenolic compounds and antioxidant activity for the first time. A high performance electrospray ionization mass spectrometry (HPLC-UV-ESI-MS) method was developed for the rapid identification of phenolics in extracts from peels and juices of all species. Several flavonoids including one kaempferol-O-hexoside (peak 16) and one hesperidin derivative (peak 22) three quercetin derivatives (peaks 4, 19 and 36), five isorhamnetin derivatives (peaks 5, 23, 24, 26 and 29) four luteolin derivatives (peaks 14, 25, 27 and 40), seven apigenin derivatives (peaks 2, 3, 12, 20, 34, 35 and 39), seven diosmetin derivatives (peaks 7-9, 17, 21, 31 and 37), three chrysoeriol derivatives (peaks 10, 18 and 30), and four eryodictiol derivatives (peaks 6, 13, 15 and 38) were identified in negative and positive mode using full scan mass measurements and MSn fragmentations. Ascorbic acid content was higher in the pulps of the varieties Genova and Sutil (60.13 ± 1.28 and 56.53 ± 1.06 mg ascorbic acid per g dry weight, respectively) while total phenolic content was higher in Pica peels followed by Sutil peels (34.59 ± 0.81 and 25.58 ± 1.02 mg/g GAE dry weight, respectively). The antioxidant capacity was also higher for Pica peels (10.34 ± 1.23 μg/mL in the DPPH assay and 120.63 ± 2.45 μM trolox equivalents/g dry weight in the FRAP assay). The antioxidant features together with the high polyphenolic contents can support at least in part, the usage of the peel extracts as nutraceutical supplements, especially to be used as anti-ageing products. © 2014 by the authors; licensee MDPI.Ítem Metabolomic Analysis of Two Parmotrema Lichens: P. robustum (Degel.) Hale and P. andinum (Mull. rg.) Hale Using UHPLC-ESI-OT-MS-MS(MDPI AG, 2017-11) Torres-Benítez, Alfredo; Rivera-Montalvo, Mariá; Sepúlveda, Beatriz; Castro, Olivio N.; Nagles, Edgar; Simirgiotis, Mario J.; Garciá-Beltrán, Olimpo; Areche, CarlosLichens are symbiotic associations of fungi with microalgae and/or cyanobacteria. Lichens belonging to the Parmeliaceae family comprise 2700 species of lichens, including the Parmotrema genus which is composed of 300 species. The metabolites of this genus include depsides, depsidones, phenolics, polysaccharides, lipids, diphenylethers and dibenzofurans, which are responsible for the biological activities reported including antidiabetic, antihelmintic, anticancer, antioxidant, antibacterial, anti-inflammatory, antimitotic, antitumoral, antifungal, and antioxidant enzyme inhibitory. Due to scarce knowledge of metabolomic profiles of Parmotrema species (P. andinum and P. robustum), a full metabolome study based on ultra-high performance liquid chromatography-diode array detector-electrospray ionization-quadrupole-orbitrap-mass-spectrometry (UHPLC-DAD-ESI-Q-orbitrap MS) was performed for a comprehensive characterization of their substances. From the methanolic extracts of these species, a total of 54 metabolites were identified for the first time using this hyphenated technique, including thirty compounds in P. andinum, and thirty-seven in P. robustum. Moreover, two compounds were not identified as known compounds, and could be new structures, according to our data. This report shows that this technique is effective and accurate for rapid chemical identification of lichen substances and the compounds identified could serve as chemotaxonomic markers to differentiate these ruffle lichens. © 2017 by the authors.Ítem Microwave-Assisted Extraction of Secondary Metabolites Using Ethyl Lactate Green Solvent from Ambrosia arborescens: LC/ESI-MS/MS and Antioxidant Activity(Multidisciplinary Digital Publishing Institute (MDPI), 2024-05) Guillen, Evelyn; Terrones, Hector; de Terrones, Teresa Cano; Simirgiotis, Mario J.; Hájek, Jan; Cheel, José; Sepulveda, Beatriz; Areche, CarlosAlternative solvents are being tested as green solvents to replace the traditional organic solvents used in both academy and industry. Some of these are already available, such as ethyl lactate, cyrene, limonene, glycerol, and others. This alternative explores eco-friendly processes for extracting secondary metabolites from nature, thus increasing the number of unconventional extraction methods with lower environmental impact over conventional methods. In this context, the Peruvian Ambrosia arborescens was our model while exploring a microwave-assisted extraction (MAE) approach over maceration. The objective of this study was to perform a phytochemical study including UHPLC-ESI-MS/MS and the antioxidant activity of Ambrosia arborescens, using sustainable strategies by mixing both microwaves and ethyl lactate as a green solvent. The results showed that ethyl lactate/MAE (15.07%) achieved a higher extraction yield than methanol/maceration (12.6%). In the case of the isolation of psilostachyin, it was similar to ethyl lactate (0.44%) when compared to methanol (0.40%). Regarding UHPLC-ESI-MS/MS studies, the results were similar. Twenty-eight compounds were identified in the ethyl lactate/MAE and methanol/maceration extracts, except for the tentative identification of two additional amino acids (peaks 4 and 6) in the MeOH extract. In relation to the antioxidant assay, the activity of the ethyl lactate extract was a little higher than the methanol extract in terms of ORAC (715.38 ± 3.2) and DPPH (263.04 ± 2.8). This study on A. arborescens demonstrated that the unconventional techniques, such as MAE related to ethyl lactate, could replace maceration/MeOH for the extraction and isolation of metabolites from diverse sources. This finding showed the potential of unconventional methods with green solvents to provide eco-friendly methods based on green chemistry.Ítem Phenolic Compounds in Chilean Mistletoe (Quintral, Tristerix tetrandus) Analyzed by UHPLC–Q/Orbitrap/MS/MS and Its Antioxidant Properties(MDPI AG, 2016) Simirgiotis, Mario J.; Quispe, Cristina; Areche, Carlos; Sepúlveda, BeatrizMass spectrometry has become a method of choice to characterize bioactive compounds in biological samples because of its sensitivity and selectivity. Hybrid ultra-HPLC hyphenated with Orbitrap mass analyzer is an innovative state of the art technology that allows fast and accurate metabolomic analyses. In this work the metabolites of a Chilean mistletoe endemic to the VIII region of Chile were investigated for the first time using UHPLC mass analysis (UHPLC-PDA-HESI-Orbitrap MSn). The anthocyanins, together with the non-pigmented phenolics were fingerprinted and correlated with the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP), the superoxide anion scavenging activity assay (SA), and total content of phenolics, flavonoids and anthocyanins measured by spectroscopic methods. Six anthocyanins were identified, and among them, the 3-O-glycosides of delphinidin and cyanidin were the major ones. In addition, several phenolic acids (including feruloylquinic acid, feruloyl glucose, chlorogenic acid) and several flavonols (luteolin, quercetin, apigenin, isorhamnetin and glycoside derivatives) were also identified. The mistletoe leaves showed the highest antioxidant activity as measured by the DPPH radical bleaching, ferric reducing antioxidant power and superoxide anion scavenging activity tests (13.38 ± 0.47 µg/mL, 125.32 ± 5.96 µmolTE/g DW and 84.06 ± 4.59 at 100 µg/mL, respectively).Ítem Seco-taondiol, an unusual meroterpenoid from the Chilean seaweed Stypopodium flabelliforme and its gastroprotective effect in mouse model(MDPI AG, 2015-04) Areche, Carlos; Benites, Julio; Cornejo, Alberto; Ruiz, Lina M.; García-Beltrán, Olimpo; Simirgiotis, Mario J.; Sepúlveda, BeatrizTen known meroterpenoids and the new meroterpenoid 7 were isolated from the Chilean seaweed Stypopodium flabelliforme as their acetylated derivatives. Furthermore, the known metabolite taondiol has been isolated for the first time from this species. The molecular structure of the new metabolite was determined by spectroscopic methods based on 1D- and 2D-NMR. Isolation of 7 represents a key step toward a better understanding of the biogenesis of this class of meroterpenoids. Among the meroditerpenoids isolated, stypodiol, isoepitaondiol, epitaondiol and sargaol exhibited gastroprotective activity on the HCl/Ethanol-induced gastric lesions model in mice. Regarding the mode of gastroprotective action, the activity of epitaondiol was reversed significantly when animals were pretreated with indomethacin, N-ethylmaleimide and N-nitro-l-arginine methyl ester (L-NAME) suggesting that prostaglandins, sulfhydryl groups and nitric oxide are involved in their mode of gastroprotective action. In the case of sargaol the gastroprotective activity was attenuated with indomethacin and N-ethylmaleimide, which suggests that prostaglandins and sulfhydryl groups are also involved in the mode of action using this model.Ítem UHPLC-MS Metabolomic Fingerprinting, Antioxidant, and Enzyme Inhibition Activities of Himantormia lugubris from Antarctica(MDPI, 2022-06) Areche, Carlos; Parra, Javier Romero; Sepulveda, Beatriz; García-Beltrán, Olimpo; Simirgiotis, Mario J.Himantormia lugubris is a Chilean native small lichen shrub growing in the Antarctica re-gion. In this study, the metabolite fingerprinting and the antioxidant and enzyme inhibitory potential from this species and its four major isolated compounds were investigated for the first time. Using ultra-high performance liquid chromatography coupled to quadrupole-Orbitrap mass spec-trometry analysis (UHPLC-Q-Orbitrap-MS), several metabolites were identified including specific compounds as chemotaxonomical markers, while major metabolites were quantified in this species. A good inhibition activity against cholinesterase (acetylcholinesterase (AChE) IC50: 12.38 ± 0.09 µg/mL, butyrylcholinesterase (BChE) IC50: 31.54 ± 0.20 µg/mL) and tyrosinase (22.32 ± 0.21 µg/mL) enzymes of the alcoholic extract and the main compounds (IC50: 28.82 ± 0.10 µg/mL, 36.43 ± 0.08 µg/mL, and 7.25 ± 0.18 µg/mL, respectively, for the most active phenolic atranol) was found. The extract showed a total phenolic content of 47.4 + 0.0 mg of gallic acid equivalents/g. In addition, antioxidant activity was assessed using bleaching of DPPH and ORAC (IC50: 75.3 ± 0.02 µg/mL and 32.7 ± 0.7 μmol Trolox/g lichen, respectively) and FRAP (27.8 ± 0.0 μmol Trolox equivalent/g) ex-periments. The findings suggest that H. lugubris is a rich source of bioactive compounds with po-tentiality in the prevention of neurodegenerative or noncommunicable chronic diseases. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.